MSMQ or Service Broker or bulk insert for FIFO message processing?

Question

We have a scenario where we need to use update/insert queries to the database against incoming real time events. We can go for either of the options presented below 1- MSMQ 2- SQL Service Broker 3- Custom built caching mechanism (using file cache, Bulk Inserts, triggers to convert inserts into updates if rows already exist etc)

We are not using an transactions, what should be the best option?

If we decide to use MSMQ, there is no guarantee about the ordering of the messages, we want it FIFO. So far best approach seems to be our own implementation but if MSMQ or Service broker can provide FIFO message processing it would be real nice.